Excavating tooth components



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I v v BYPAUL EYOLFSN im m United States Patent 3,496,658 EXCAVATINGTOOTH COMPONENTS Paul Eyolfson, Portland, Oreg., assignor to EscoCorporation, Portland, 0reg., a corporation of Oregon Filed Dec. 22,1967, Ser. No. 693,008 Int. Cl. E02f 9/28 US. Cl. 37-142 4 ClaimsABSTRACT OF THE DISCLOSURE Excavating tooth components wherein the usualmating wedge faces are modified to include longitudinally extendinggrooves and ribs for interlocking connection so as to eliminate the needfor a locking key.

Summary of invention Since the advent of two-piece excavating teeth atleast as early as 1900, there has been a continuing problem with lockingthe point securely on the adapter. If the lock was so secure as tocompletely insure connection under all types of digging, it wasvirtually impossible to replace the wearable point on the adapter. Onthe other hand, if the lock were easily releasable, there was always thepossibility that the key would become removed during harsh digging withthe attendant loss of the point. This would leave the adapter exposed,requiring expensive and extensive repairs to the bucket, dipper, etc.,which carried the excavating tooth.

According to the instant invention, I avoid the need for any lockingkey, making use of novel mating parts on the component of the excavatingtooth and the provision of such a component and the composite assemblyconstitute important objectives of this invention.

The invention is explained in conjunction with an illustrativeembodiment in the accompanying drawing in which:

FIG. 1 is a perspective view of an assembled point and adapter making upan excavating tooth constructed in accordance with the teachings of thisinvention;

FIG. 2 is a perspective vie-w of the components of FIG. 1 shown indisassambled condition; and

FIG. 3 is an enlarged sectional view such as would be seen along thesight line 33 applied to FIG. 1.

In the illustration given, the numeral 10 designates generally anexcavating tooth which is seen to include an adapter 11 and a point 12.The point is considered the wearable or replaceable portion and is thepart that engages rocks, gravel, etc. principally through its cutting ordigging edge 13. Generally, the point 12 has a hollow-Wedge shape with asocket 14 (see FIG. 2) opening to the rear of the point 12.

The adapter 11 is constructed to be mounted on the forward edge of anearth-handling device such as a dragline bucket or shovel dipper and forthat purpose has a key receiving opening 15. From the forwardshoulderproviding faces 16, the adapter 11 has a pair of noses 17and 18separated by a discrete space 19 in which a web 20 longitudinallybisecting the socket 14 is received.

The essentially corrugated nature of the interior of the socket 14 andthe wedge faces of the noses 17 and 18 can be appreciated from aconsideration of FIG. 3. In FIG. 3, it will be seen that a plurality ofa substantially identical longitudinally extending ribs 21, 22 and 23are provided on the upper wedge face of the nose 17. Identical ribs areprovided as at 24, 25 and 26 on the lower wedge face of the nose 17. Inthe illustration given, the nose 18 is similarly equipped. As a specificexample of the invention, the tooth pictured may be a 4.5" nominal sizewherein this dimension is essentially the transverse ice dimension ofthe nose assembly, i.e., the dimension ranging from the right-hand sideof nose 17 to the left-hand side of nose 18. In such a case, the pitch Pdimension is 0.5", the valley is 0.12", the root spacing S is 0.06", andthe overall engagement height of a rib and groove is 0.31". It will beseen that a plurality of convergent planar faces are provided on thegrooves and ribs of each nose and socket so as to provide a substantialfrictional engagement between the point and the adapter.

In operation, the stresses encountered usually have a substantialcomponent extending rearwardly along the mid-longitudinal plane of theassembled tooth which tends to drive the point more securely intoseating engagement with the adapter noses. Because the ribs and grooveson each of the noses and the socket are substantially identicallyoriented, this provides a. maximum of frictional hearing so that it isextremely diflicult to remove the point from the adapter. In practice,it has been found that even making use of a sledge hammer and drift pinto apply force in the direction designated F in FIG. 1 is inadequate toremove the point from the adapter. Removal, however, is facilitated byvirtue of relieving a portion of the upper face of the point as at 27for the insertion of a Wedge (not shown). A wedge inserted into therelief 27 bears conjointly against the web '20 and the Wall 28 definingthe rearward extent of the recess 19 so that tremendous dislodgingforces can be applied with a relatively small force applied to thewedge-type drift pin--thereby facilitating disengagement of the pointfrom the adapter.

It should be appreciated that the invention here makes possible theelimination of the locking key as the means for holding the point andadapter in engagement after they have been properly joined. However, insome cases, the locking key can be used to advantage. For example, asmall tooth point of a size similar to a P-2 trencher point could bevery easily installed with a 2-pound hammer, and no locking key isnecessary. At the other extreme, where a ZOO-pound point is applied to a13" nominal size tooth, it is quite obvious that a 2-pound hammer wouldnot have sufficient weight to provide the degree of impact that isnecessary to overcome the inertia of the tooth point. Thus, unless theartisan went to approximately a to 300-pound sledge hammer, it would beimpossible to have the invention function and lock the components inplace. In the extremely large tooth points, it will usually be necessaryto install the tooth point and hold it in place with a locking keyusingthe power of the shovel or dragline to push the tooth point against therock in order to properly accomplish the initial installation. Fromthis, it can be seen that there can be no holding power attributed tothe fluted bearing surface unless a sufiiciently high bearing load is inexistence.

From the foregoing, it will be appreciated that the degree of holdingpower will also depend upon the stresses encountered. Normally, verysmall teeth are subjected only to small stresseshence only limitedbearing is needed. In the very small types of teeth, it is possible toadvantageously practice the invention with only one flute on one bearingsurface.

In the illustration given, it will be noted that the flutes on the noseportion 17 and 18 extend substantially the length of the responsivenoses. However, those skilled in the art realize that the fluted bearingsurfaces at the tip of the nose may not be sufficiently large to keepbearing loads at a safe level under heavy beam-bending loadings.Therefore, so as to avoid the peening or crushing of various flutes, itmay be desirable in some instances to terminate the flute short of thenose tip. This can be done by making a partial flute which starts as afull flute at the rear of the nose and fades out to a flat, single bear-3 ing surface at the tip of the nose. In this manner, the locking poweris concentrated in the rear third of the nose area, yielding maximumbearing surface Where it might be needed.

By the term generally longitudinally-extending, I contemplate not onlythe parallel flutes depicted herein but also those that depart fromsubstantial parallelism, i.e,, slightly fan-shaped. This is possiblesince there is adequate clearance during installation until full matingcontact is achieved.

I claim:

1. A replaceable edge part for an excavating device comprising a unitarybody having a ground engaging edge at the front end thereof, said bodyhaving a longitudinal axis extending from the front end to the rear endand along which said edge part is moved for installation on an edge partholder, said body adjacent the rear end being equipped with facesadapted to mate with corresponding faces on said edge partholder, eachof said body faces extending generally longitudinally of said body andbeing convergent longitudinally of said body, each of said body faceshaving a plurality of longitudinally extending spaced apart groovestherein, grooves being parallel to each other and to said longitudinalaxis, each of said grooves having substantially identical crosssectional dimensions for at least one-third of its length, and each ofsaid grooves being defined by side walls, in the area of sub stantiallyidentical cross-sectional dimensions, which side walls each form anobtuse angle With the bottom of the groove and diverge, from each otheras they extend from the bottom of the groove.

2. The structure of claim 1 in which said body faces are upper and lowerforwardly convergent surfaces interiorly of said body to define a socketin the rear of said edge part.

3. In combination, a replaceable edge part for an excavating device andan edge part holder therefor, said edge part comprising a unitary bodyhaving a ground engaging edge at the front end thereof, said body havinga longitudinal axis extending from the front end to the rear end andalong which said edge part is moved for installation on said edge partholder, said body adjacgnt the rear end being equipped with facesadapted to mate with corresponding faces on said edge part holder, eachof said body faces extending generally longitudinally'of said body andbeing convergent longti-udinally of said body, each of said body faceshaving a plurality of longitudinally extending spaced apart groovestherein, said grooves being parallel to each other and to saidlongitudinal axis, each of said grooves having substantially identicalcross sectional dimensions for at least one-third of its length, andeach of said grooves being defined by side walls, in the area ofsubstantially identical crosssectional dimensions, which side walls eachform an obtuse angle with the bottom of the groove and diverge from eachother as they extend from the bottom of the groove, said edge partholder being equipped with flutes on said corresponding faces engagingthe side walls of the edge part grooves.

4. The structure of claim 3 in which said body faces are upper and lowerforwardly convergent surfaces exteriorly of said body to define a socketin the rear of said edge part, said edge part holder corresponding facesbeing upper and lower forwardly convergent surfaces defining a noseportion received in said socket.

References Cited UNITED STATES PATENTS 1,837,341 12/1931 Shaffer 371422,124,230 7/1938 Hosmer et al 37-142 2,256,488 9/1941 Murtaugh 37--1422,982,035 5/1961 Stephenson 37l42 3,121,289 2/1964 Eyolfson 371423,349,508 10/1967 Petersen 37142 EDGAR S. BURR, Primary Examiner

